Plate glass surfacing table



May 2, 1939. w. OWEN PLATE GLASS SURFACING TABLE Filed March 29, 1958 v 3 Sheets-Sheet 2 O O 0 o O. 0 0 O O O .IIINHHU O O J 10 o 0 INVENwR. Wh. L. mM O wE/v y@ I A RNEYS.

May 2, 1939. W QWEN 2,156,699

PLATE GLASS SURFACING TABLE @M TTDRNEYS.

Patented May 2, 1939v PATENT oeils f 2,156,699 PLATE GLASS snaraomo TABLEv william owen, Pittsbnrgh, ra., ssignor to Pittsburghllate. Glass Company, Allegheny County, Pa., a corporation oi.' Pennsylvania Application March 2s., i938, serial Nn. 198,674

s o iaims. (ci. slt-240') c The invention relates to tables for use in surfacing plate glass, in which the tables are passed L Vin a contlnuoustrain beneath a series of grinding and polishing runners. The heat developedA in the polishing operation causes the tops of the tables to warp or' bow slightly, so that they are 'no longer true and fiat, and when returned to the grinding end of the cycle for reuse, this bowed or warped condition persists to acertain extent,

p sothat the glass sheets are. not ground to uniform thickness, the sheets being ground thinner in the portions overlying the centers of the tables than those overlying the sides of the tables. The object of the present invention is to provide an i improved table construction, in which the Warping of the table tops due to the heat developed in polishing is substantially. eliminated. Briefly stated, this is accomplished by employing a table of ordinary construction, but provided with a false 9 top with a space beneath supplied with a cooling iiuid, ilns being provided onl the lower side of the false top to promote the rapid conduction of heat from such top to the fluid. The cooling iluid may be circulated through the space between 5 the two tops, while the table is passing beneath the polishing section of the'surfacing system,l or such space may merely be lled with the uid, such as watenwhen lthe table starts past the polishing section, followed by a removal thereof n at the end of such section. Certain embodiments oi the invention are illustrated in the drawings, wherein:

Figure lis a plan view. of a part of the table. Fig. 2 is a transverse section on the line Il-l-II of 5 Fig. l. Fig. 3 is an enlarged section on the line IlI--Ill of Fig..1. And Figs. 4, 5 and 6 are views similar to Figs. 1, 2 and 3, but showing a. modification. 4 j

Referring to the drawings, the table comprises ,0 a body portion consisting of theA top reinforced by the ribs 8 and-9, the wheels lila suitably ab1 tached to the body portion and riding-upon the rails IB. Seated upon the top l, but/spaced away therefrom is a false top comprising the plate il La which is provided'on its lower side with the series of ilns or ribs I2, the plate Il being preferably a castingwith the ribs integral therewith. These ribs are of tapering shape, as indicated in Fig. 3, and their vlower ends, which are all machined to io `the same plane, rest uponthe top l. The plate Il is clamped securely to the top 'l by means of a [plurality of clamping bolts I4 distributed over the area of the table and screwed into lugs lli which are also integral with the plate 1i. provides a very rigid support for the false top il carrying the glass sheetto he surfaced. A sheet la ci insulating material, such as vulcanite or Bakelite. 'may be employed to further retard a transfer of' heat to the plate 1.

In order` to `provide for the cooling of the false s top il, so that it will not warp during the polish .ing operation, provision isfmade for circulating a cooling fluid through the space I6 during the period in which the tables are passing beneath the polishing section of the surfacing apparatus. l@ This result is accomplished by the use of a plurality of nozzles l1 arranged along the line of travel of the tables. The cooling uid may be either compressed air or water. The 4circulation of this fluid through the space i5 prevents the top 'l from l5 being heated, sov that it will Warp, and the heat the space I6.V The plate II lathercfcre, maln- 25' tained at a much lower temperature than would be possible if the radiating iins i 2 were not ernployed. Due to the stiiening eii'ect of the hns, it` is also possible to make the plate li of less thiclau ness than would otherwise Ybe the case, 'so that 3@ the heatl conduction through the plate is increased, and there is less tendency Vto warp because of its relatively lower temperature.

Figs, il to S illustrate s. modification which differs from that of Figs. 1 to 3, only in the method $5 `ci cooling the space between the plates l and it and in the detail that the fins i3 extend longitudinally of the table instead of transversely" thereof. The space between the two plates is in this caseclosed by the ilanges I9, I9, so that a t@ closed space is provided, instead oi.r4 one havins' openings at its edges, as is the case in the first form of construction. Means are provided for nlling the space between the pistes in the form i of a pipe 2li which leads -to the side of the table et and is provided with a hose connection 2 l. When the table reaches the polishing section of vthe system, a water supply connection yis attached at 2| and the space between the plates l .and il is filled with water. This supplyof water is main- 50 tained in the cooling space until the table passes the polishing section, at which time, it is drained out through the connection ti or through some other suitable outlet. In order to permit the space between the plates to dll up completely, an liti air vent 22 is provided. When the space is completely lled with water, this vent is closed by screwing in the vent plug 23. In this construction, as in that of Figs. 1 to 3, the use of the fins I8 provides for the rapid transfer of heat from the false top Il to the body of water therebeneath, 'so that the top Il is heated during'the polishing operation to'l a much'lower temperature thanwouldotherwise be the case and any warping incident to the heating of the plate is, therefore, reduced. v What I claim is: y

1. A plate glass surfacing table comprising a metal body portion with a flat upper face, a false top comprising a metal plate having a at upper surface in parallel with said face for receiving the glass to be surfaced, and having on its lower side distributed thereover, a plurality of elongated fins integral with the plate with their ends in opposition to the upper face oi' the body portion and acting as spacers, means for clamping the false top against the face of the body portion, and means for supplying a cooling fluid to the space beneath the false top.'

2. A plate glass surfacing table comprising a metal body portion with a flat upper face, a false top comprising a metal plate having a flat upper ,sjurface in parallelwith said falce for receiving the glass toA'be surfaced, and having on its lower side distributed thereover,a plurality of elongated ns integral with *the platelwi'th their ends"'in.,

opposition to the upper face of `thebody portion and acting as spacers, means for clamping the false top against the face of the body portion, and meansl for supplying a cooling fluid to the space beneath the false top, said ns tapering in cross section from their upper to their low'er end's`:-.

3. A plate glassv surfacing table comprising a metal body portion-with a flat upper face, a false top comprising a metalA plate having a flat upper surface in parallel with sa'ld'iace for receiving the glass to be surfaced, and having on its lower side distributed thereover, a plurality of elongated fins integral with the plate with their ends in opposition to the upper face of the body portion and acting as spacers, means for clamping the 'false top against the face of the body portion,

WILLIAM OWEN. 

